Hello, I am disappointed with 5.0.3+ non functional landscape mode, so I would like to try downgrade to 5.0.1
The problem is, that on Amazon is only the newest firmware downloadable.
Could someone post firmware 5.0.1 ?, maybe 5.0.0 or 5.0.2, filename is Update_Kindle_5.0.1.bin. Thank you very much.

I agree with varnie. Updating newer firmware might brick your device.
But still, there is a way how to downgrade.
You can do it over RUNME script or ssh somehow described here.
In this link you can download whole Touch system, but I don't know, which version it is.

The rewriting is made by dd if=/mnt/us/mmcblk0p1.img of=/dev/mmcblk0p1 bs=4K command and it probably delete all personal data. Also it might be dangerous, if you write this command wrong.

You won't be able to apply older updates than are installed - Amazon software checks for it on Kindle itself.
And good for you it doesn't allow this, because if it would allow installing that update you'd get your device bricked with 99% probability.

Hello, I am disappointed with 5.0.3+ non functional landscape mode, so I would like to try downgrade to 5.0.1
The problem is, that on Amazon is only the newest firmware downloadable.
Could someone post firmware 5.0.1 ?, maybe 5.0.0 or 5.0.2, filename is Update_Kindle_5.0.1.bin. Thank you very much.

You can downgrade by flashing (dd) your mmcblk0p1 partition with the 5.0.0 "forensic" image from the "Select Boot" thread, and erase the /var/local partition (copy /dev/zero to /dev/mmcblk0p3). Be sure to backup your collections or other valuable information first.

You can downgrade to other versions too if you get partition copies from somebody. If you downgrade from 5.0.4, you should (probably) also flash a copy of the older main linux kernel (which upgraded with the 5.0.4 update).

@diba: rotation hack is no longer fully functional under 5.0.4, you can just select between:
1) missing characters on the end of line, but images are OK (GUI Launcher)
or
2) cut off images, but text on the end of line is OK (KT_Rotation)

or which hack exactly I have to use for fully functional landscape reading (pdf) ?

I use the reader for reading, so I would accept the cropped pictures, if I would read landscape. For me it is ridicolous trying to go back to an older firmware with all the risks of bricking implied.
But its your choice.
AFAIK the rotaion hack has only implications on mobi/azw, not on pdf. But not sure.

You provided a link to the WRONG data.tar.gz. This one ONLY works while booting from the main partition. To write to main, you MUST boot from the diags partition, which needs a data.tar.gz that works in diags.